Hypodermic syringe



Oct. 20, 1925. 1,557,837

G. N. HEIN HYPODERMIC SYRINGE Filed Harsh 28. 1925 [Heier Patented Oct. 20, 1925.

anew-me Sinnen Kppii'etwifid 'Haren 281925. serial No. 19,034.

mail' @Dimm may memis@V it known. um' r., GmsG' N. Hem..

citizen' of. the United St'tes; residing" attlif City and county of smi Ffanciseo" mi Sme of Californie, have inv'eiitedfcertfrin new' useful Improvements in H'yijle'nie Sringes, of which the' folloiiing'is" i Spesiflea'- ti'n.

This invention relates' tozt'li Clae ofliypoderin syringes,V andj espeoiallfy' tothat? type, such, for example', tih'seliov. welll lnovn as the L uer?, in. ivliiehj the iiitoir eorrepoiids to the diameter' of' theAL Barrel? andV isv self' containing' and pecking in eliil zic'te'r', said piston being adpe'dL tdbe" fully Withdrawn from the' barrel to enallethez solution to be pb'urecli into` the4 upper' or'- bfeech @iid of the' bari-e1 from a einen@ ofi talinjer" or piQe't-te'; 2U There re two methotljof fillingy fi' tiallj filliig`g`V a; Syringe. First, loy'fll7- prof j'ecting the piston. iii the" ltrriili.their merging the needle oi" nippleiil ff the bi' i'lin" the solution, and theil' dia'wiirigfup'tli solution through the needle into the"v B'a'el B51 the r'triog"'resilvez"Iri'cv'eriiuiti ofthe I'iston. Se'ilch when usingy a'yring'eolf th-li-e Inertioned'tfpe, tht is`,.on'litfi ng pifsfti go related tothe' barrel Sft' be# self'.l fr'i t'inedand pae'ked, initially" Wthdtvig gfiicll piston 'cornpl'etely y from the Barrel" ls'o that the-upper or breech entlftli'liztel is exposed, then pouring into' seicl openj end the charge of Slutio'n arnltheirI Ife'inerfliilT the" piston: The lat-ter n'etlodisl the' one ehoic ais-it insures safety` c'ntiniziftion of the sterile solution ndisjeipdtious; This method isf, however, open'to the bbjecf tion of lacking air venting inl vpiton :stabilizing as Will be presently' fillyl eiil. plnedi l It is' theobjeet" of the p'reent invention to overcomeY thisbjetion and" to .filit'te the filling ofthe syringe by providing' ineens for expelling" o' venting ,the ai" frr'ntlie barrel andfoi" stabilizing the" piston' upon itsm entiende.,

In order toiniore fully: uhlestantlf tliiS abject. it mayb@ lpointed out mi; iriiin a 'syringe frein' the upe'r 'oi' liree'eliecl the barrel, the instrument is; ulsiill'y'" l'eld at a vslight angle, the iife'edle bigjifplce, and, owing to its Smallopening', Wil eie suliic-ient-capillary attraction to prevent the Solution froinesepig through it. But im- 11H61 prsief invention contemplates" the a spring memberl pressing on air vent of Fig. 1, but with the addition of the entering piston. y l.

Fig. 11 is a sectional view showing a vent in the wall of the piston and a spring meinber operating through said'vent and pressing on the piston, said member also beingY associated with and serving to finger grips.

Referring to 1 is the barrel of the syringe and 2 isf the needle thereof. 3 is theiin'ger grip. 4 is the piston and 4 is the packing. l

In the inner surface of the `breech end Vhold the of the barrel is made a longitudinally `d i,l

When, therefore, the piston having been withdrawn from the barrel, andthe latter supplied with the solution, through theopen end of the barrel up to about the inner end` of the groove 5 and the piston is then entered, as in Fig. 1, it will drive the air which lies between the upper limit of the solution and the end of the barrel, out through the vent groove 5, and said piston will reachy a stable position without having imposed any pressure upon the solution. v. .y Referring to Figs. 4 and, it will be seen that theair vent assumes the form Vof a slot 6 passing through the wall of the barrel extension.

In Fig. 6 the airvent 7 is port opening throughl the barrel wall. Y

In Fig. 7 the air vent is in the rform of a slightly enlarged interior annular passage 8 about the piston. u n

In Figs. 8 and 9 the piston end hasa venting groove 9 which until the piston isr stabilized leads the air past the packing.

In Fig. 10 the form of the vent 5 is the same as the groove of Fig. 1, but in order to further insure the stabilityV of the piston there is provided a spring wire 10 whichl clamps about the beaded head of the barrel and has an extension 11 which hooks into the end of the groove 5 and presseson the piston.-

In Fig. 11 a'spring wire ,12 has a bearing end 1 3 which presses `uponthe piston through an air vent port 14 in thepiston wall, This spring Wire is connected withl the annular hub 15 of the finger guards 16, which Yhub is slipped upon ,thel barrel. and abuts against the end bead thereof, Aand is there held by the spring wire 12.` y

Obviously, the piston groove 9 may or may not `be used in conjunction with the barrel side vent 7 of Fig. 6 ,orlthe similar lvent 14 in Fig. 11. In case saidl groove 9 is used, as is illust-rated in Fig. 11,'the piston 4 may be driven `past the vent aperture 14, as shown,

Figs. 1,2 and 3, t-he numeral in the forni vof and then may be rotated, to turn the slot 9 away from said vent 14, thereby preventing leakage when the syringe is inverted, and thus making the operation of filling the barrel and starting the piston less exacting eventha'nf in the previously described forms.

1. A syringe ofthe type described, comprising a piston, a barrel therefor having a stabilizing portion for the entering piston extending beyond Lthe upper limit of its solution content, said stabilizingy portion having a vent for the escape of air driven therefrom by said piston as it enters.

2. A syringe of the type described,-com prising a piston, a barrel therefor having a stabilizing portion for the entering piston extending beyond the upper limit of its soluf tion content, said stabilizing portionhaving a vent for the escape of air driven therefrom by said piston as it enters, and a guard mem,-Y

ber carried by the barrel and pressing on the piston to hold it in said st'abilizingportion.

v3. A syringe of the type described comprising a-piston, a barrel therefor having a stabilizing portion for the entering piston extending beyondl the upper limit of its solution content, said stabilizing portion having a vent in its wall for the escape of air driven therefrom by said piston as it enters; and a guard member carried bythe barrel and pressingv on theV piston through said vent to hold said piston stable in said portion.

4. A syringe of the type described,v com-k prising a piston, a barrel therefor having `a'. stabilizing portion for the entering piston extending beyond the upperA limit of'its solution content, saidY stabilizing portion having a vent in its wall for the' escapeof Y airl driven therefrom by said piston as it enters; a guard member carried by the barrel and pressing on the piston through said vent to hold said piston; and a finger guard member embracingly ,fitted upon said por` tion and connected with said guard member.

g5. In a syringe of the type described, a barrel, and a rotatable and longitudinally movable piston cooperating therewith, said barrel, beyond the upper limit of its'tsolu-v tion content, provided with a stabilizing portion for said piston and havingV a vent beyond the upper limit of itssolution content for the escape of air ydriven from the barrel by said piston, and saidvpistony having a longitudinally disposed groove extending upwardly from its entering end and 'adapted to be moved into and out of registry with said vent by the rotation ofsaid piston with-V in said barrel.`

u GEORGE N. HEIN; i 

